Safety control for power presses



4Maw 2s, 1929. E W, ZEH 1,715,180

SAFETY CONTROL FOR POWER PRESSES Filedrnec. 1s, 192s 2 sheets-sham l 7 ATTORNEYS,

May 28, 1929. E. w. zEH 1,715,180

SAFETY CONTROL FOR POWER PRESSES Filed Deo. 15, 1926 2 Sheets-Sheet 2 ATT'oRNEYa Patented May Z8, QZQQ U if? ni-)Munn w. anni, or NEWARK, new'mieseYLv f SAFETY CONTROL FOR rownnrnnssns.

Application flied December i3, i926. seriai No. 154,376.

This invention relates to apparatuifi for reducing or preventing ,injury to operators of power presses or similar machines hy rendering it practically impossible for an operator to insert either hand between the dies of the press or other moving iaits of 'the Vniachine while-the press or machine is in eperation, for example while one die is moving toward the other; and more particularly the invention contemplates the constant employment of each hand of the operator at one safe position to start the machine` in operation so that the machine' cannot he started while either hand is otherwise engaged,` as in adjusting work between the dies, whereby possibility of injury to the hand hy the moving parts of the machine is eliminated,

One object ofthe invention is to provide control inechanisui for a machine which shall require inanual operation and employment of both hands of the operator at certain positions at the same time for actuation, to start the machine in operation., said means beingautomatically actuated so that upon removal of either hand from said certain position it is necessary to release the other hand loefore operation of the inachine'can again he started after stopping.

'Another object is toy provide mechanism of the character described comprisingtwo series of parts, Veach series to loe actuated hy one hand of the operator and said two series being arranged to cooperate so that both must loe manually actuated in acertain order to start operation of the machine, each vseries heine automaticall returned to normal )osition upon manual release thereof.

Other obliects areto provide suoli a mechanisin whereby it is impossible after the machine has stopped to `start the machine until both series of parts have been released to normal position; to provide a mechanism of this character wherein each of said series of parts is operated hy adifferent hand lever which is disposed at-a safey position relative to the moving parts of the machine and c'onvenient with respect to the operator and the work bed of the machine; to thus provide a safety apparatus which is foolproof and will prevent Ainjury to the operators hands in spit of any attempts he may take to heat the apparatus or use his hands while the inachine is being started for any purpose other than to properly operate said mechanism ,f to

` downwardly, as illustrated, said clutchy pinprovide. such a safety apparatus which may types of control mechanisms so as to have'a wide :held oit use; to provide a safetydevice which shall'lie simple and inex )ensive in construction and operation, and to obtain-other resultsand advantages as' mayl beibrought out'liy the following description. A

Referring to the accompanying drawings,l in which corresponding and like parte are the saine reference characters, I

Figure 1 is a side elevation of a power designated throughout the several views by Vpress showing a safety apparatus embodying my invention applied thereto, the driving wheelheing omitted for clearness of illustration;

Figure 2 is an elevation of the side of the vpress opposite that shown in Figure 1;

Figure y3 is 'ahorizontal sectional view, f taken on the line 3-3 of Figure 1;

' Figure 1 is an enlarged fragmentary side' elevation rof the control apparatus illustrated in Figure 1, showing the lirst step in the operation of the control apparatus to .start the press; af i Figure 5 is a similar view, showing the sec-l ond and last operation of thev control apparatus for starting the press, and

Figure 6 vis a view similar to Figure 5,

showing the effect of the operator releasing one of the control levers'whereloy the opera--y tion of the press is automatically stopped.

A For the purposevof illustrating the principles of the invention, l:l have shown it in connection with a control mechanism for a power press of known construction which includes a frame 1 having a bed 2, and head 4 adapted to be reciprocated'loy a pitm'an 5 upon the eccentric (not shown) of a shaft 6 .journaled in I the upper part of said frame 1. VA driving wheel (not shown) is loose upon said shaftV 'and adjacent to it is a clutch inemloer 7 fast upon theshaft and carrying a clutch pin 8V Vnormally projected by a spring.(not shown)y to he engaged by the driving wheel. Said clutch member 'i' is annularly slotted, and a. throw-out 9 pivoted to swing in the plane of said slot has a free inclined or vwedge-shaped end lying inesaid slot to engage the clutch pin -Y 8 and retract it fromv the drivingfwheel All said parts as described above are old and welllknown in the art so that they need no further description or illustration here, their opera! tionloeing that when'thethrow-out 9 is swung s out of ei'igagement with the clutchpin or is automatically'-'projected and engaged by.

. the driving A,wheel `fto. carry the shaft Aaround with it,i but,a'lter thefthrow-outhas been released it auton'iatically returns upwardly,`as

by a spring 10, to again engage the clutch pin at the end of a complete rotation and stop'the head 4 in raised position.y .Obviously .the

throw-out 9 may be operated by any suitable I Y' turn upwardly., iI-nffaet, the invention vmay be used llzconneetion with many different types of control mechanisms other than'fthat described.

Ingthespeciicembodiment. of .the `invention Y illustrated infthe drawings, ahorizontal .shaft 10 is journalcd for rotationon fthe :frame '1 of the press at .therearlogt .ethe hed 2, the endsfof the shaft .proj eating `beyond Ithe :frame atopposite .sides 1ofthe ibed'of the press. A To vone end of .-the'shait 1Q-is zattached lan operating hand lever l1 so thatrsaid shaftwill rotate g upon .oscillation of said-lever. A helical spring 12-is mounted upontheshatt and has its ends connected respectively 'to the `shaft and .the Aframe lot the press so thatthetorque oi saidL spring normally rotates the shaifft to swingwthe 'lever 11:1 upwardly. The lever `is provided .wfdzh opposed stop lugs 13 arranged atopposiftelsides"ost a stop pin 14cm the frame 1 @to vlimit movement of ,the flever 11 in both directions. y

Mounted :to wrotate lupon the Aother projectingr end .off fthesl-iadt 1i()- is another operating hand dever 15. "llhislever is formed with two .spaced portions 16 and .1.7 }ou.-rnaled 111 ,Y co-axial relationarpon the .shatt 10 and intevgrally ,for otherwise rigidly Yconnected by a web 18. @heeft :these portions, in the :present instance'fthe .outer .portion 16, is formed with an Varm 19.which carries a .pin 20disposed substantially parallel ,to ythe shaft 11()v and arranged in a slot '21 ilrroneendiof aconnecting liinlr-22, ,the .opposite end .of whichis ,operatively Aconnected wviththe throw-out V9 in any suitable manner, for example, -as yshown by my Patent No. 1,630,882 dated May 31, 1927. The slot 21 is right-angular in shape with one arm `23 of the angle exten-ding toward ,the shaft '1Q and .the .other arm substantially longitudinal Io-thelink 22 and vertical.V

'Arranged between .the portions 1:6 and 17 of Ythe leve-r land fiXedly connected to ,the

shaft 10 is a Acrank arm 24 which .extends upwardly and has pivotally connected lto its upper endoneV end olf a push bar 25 the tree 6nd of which normally bears against the adjacent side of the-connecting link 22. This push bar`25 is normally held at substantially iright.anglesto.theel-ank arm 24 by a lug 2S which underlies the push ba r, as clearlyy shown in .Figures-,4to Giinelusive, the push bar being` free to move up vardly to an extent limited by engagementot an extension with an yinclined surface 34 on=the lug 2G. The crank arm 24 has an extension at the sideo'l thev sha-tt 10` opposite ythe push bar 25 between whiehand the end of the connecting linlr22 is connected a tension spring-28 which tnormally vswings the ,lower end-.of :the connecting y lA-inlr22 with respect .to the pin-,20ron the arn'i 19s'o that thepin is located inthe angle of the slot 21,-as show-nin Figures 1 and ,6 O't'fthe drawings. VViththis construction, it .will ybe obvious that the cranlarm 24 lwill befoseillated by oscillation o i the hand lever 1\1 ,.while e the arm ,19 and pin 2O will be oscillated 'by oscillation of Athe hand Vlever 15, fthe mo-vementsfof'the two Vlevers andthe directly Vassociated parts-being independent ofieaeh other.

An suitable stoJainO means ma be' )ro-` vvided for 'limiting.oscillation of the `level' 15,

but A:in the present instance I Vhave;shown the lever formed with a rearward extension-29 at the side of lthe shaft 10 'opposite the arm 1S). in which vare, mounted spaced .stop screws V30 which upon oscillation yol the lever in /opposite directions -willgengage the 'frame yoithe press, Aspring 31 is mounted upon theshaiit and connected ,with Ythe. extension `29 to' normally swing the handv lever1 'lupwardly substantially in the same horizontal eplane as the lever 11. l

It will be:observedthatthe hand levers 11 and 15 are disposed at opposite sides o the bed ogfythe press and'that :they extend rbeyond the front oit the pressat .a height convenient to :the `operator so that :they may be operated by Vmerelyresting the hands t'hereon with the fore-arms in approximatelyhorizontal position. To start the press vin operation, the hand lever 11 is pushed Idownwardl y with'one hand which causes movement fol: the .crank anni v24 toward theylinl 22 and through Athe push :bar 25 swings the lower end of theconnecting linl`22 so rthat lthepin 20 isloeated -in the horizontal lportion I23 o1 vthe slot 21,1as

shown `in Figure 4 of the drawings. l/Vhile the lever v11 1s1thusl1elrl,:he lever' y15 is pushed downwardly with r.theother hand which causes downward swinging oit thea-rm 19 and the-pinf20 which through its engagement with the Yhorizontal portion oft' the slot 421 exerts a downward .pull on the connecting link 22, shown in Figure 5 .-o 'the drawings, so .that the throw-.out 9 is pulled downwardly and the clutch pin 8 permitted to engage the driv-v ing wheel. 'lf the hand lever 11 is released thev spring 12. will return .the lever to its nornial position and at the saine time move the crank arm 24 and the push bar 25 away from the link 22, whereuponthe spring 28 `will swing the link t-o locate the-verticalportion of the slot 2l in alinenient with the pin20, after which the'springactuating the throw* wardly and obliquely to the crank arm 2d as shown in Figure o of the drawings, -which will permit the spring` 28 to swing the link 22 so 'as to disengage the horizontal portion of.

the slot 2l from the pin20 and permit-'the link 22 to move upwardly and re-engage the throw-out 9. Then tov start the press it is necessary to release the lever 11, whereupon the push bar 25 falls by gravity to its normal position, and actuation ofthe levers l1 and l5 downwardly will start the press as above described.

vFrom the foregoingit will be understood that to start the press in operation, both hands of the operator must be used at the saine time, and furthermore, after one lever has been released, it is impossible to start .the press until the other lever has been returned to its normal position and the proper sequence of operation of the levers is repeated. Accordingly, it is practically impossible for the operator to use his hands for any other purpose than holding the levers 11 and l5 while the press is being started, and therefore it is practically impossible for either hand to be inserted between tlie dies of the press while the movable die is in motion.

While I have shown and described the invention in connection with a certain type of power press and a certain control mechanism, it is to be understood that this is primarily for illustrating the principles of the invention and that the invention is susceptible of use with other types of machines and the details of construction may be modified or changed without departingfrom the spirit or scope of the invention. Therefore, I do not want to be understood as limiting myself in theconstruction and use of the invention except as required by the following claims when construed in the light of the prior art.

Having thus described the invention, what I claim is:

1. Safety control apparatus for power presses or the like, comprising means for controlling the application of power to a press to operate the saine, a pair of operating members each operable by one hand of the operatoi', means including a plurality of cooperating,` parts for operatively .connecting said controlling means and one of said members to operate vsaid controlling means to start the press upon' movement of' said member in v one direction, ineens fornormally"influencing said parts of said connecting inea-usato break.

said connection between said member and said controlling` means, mea'insactuated bythe other of Vsaid operating members upon movea inent in one direction for positively relatively moving said parts of -said connecting means to make and hold said operative connection, and means for automatically actuating each of said operating members in the opposite directions to break said operative connection between the first-mentioned operating mem-` ber and said controlling means upon therelease of either or both of said operating mem'- bers by the operator. j y

2. Safety control apparatus for power presses or the like, comprising means for controlling the application of power to a press to operate the same and including a movable part to be connected to operating means, ay

pair of operating members each operable by onehand of the operator, means actuated by one of said operating members to operativelyl connect with saidpart of said controllingi means when in a certain relation thereto to imeans, and means for automatically actuating and holding said second mentioned means and the last-mentioned means in position to disconnect the first-mentioned means from said part of said controlling means upon release of either or both of said operating` meinbers by the operator. i

3. Safety control apparatus for power presses orthe like, comprisingjmeans for con trolling the application of power to a press to operate the same, a pair of operatingm'embers each operable in one direction by one hand of the operator, said controlling` means havingapart movable relatively to one of said members, said member vand said part of the controlling,` `means having cooperating separable connecting portions whereby said part may be operatively connected with saidv member when in a certain relation'thereto to actuate said controlling means to start the press upon movement of said member in said direction, means for normally holding` said spart of said controllingmeans out of said .certain relation to said member, means on the other of said operating' members for actuating' said part into said certain relation upon movement of the second-mentioned member insa'id direction, and meansfor autom atically' and normally actiiatin each of said members f in the opposite directions and holding' them so as to maintain said part disconnected from the inst-mentioned member upon release of either or both of said members. i

fl. The 'apparatus set forth in claim 3 wherein the third-mentioned means includes a movable push bar normally in position to push on said part of the controlling means,

upon movement of said secondfmentioned member 1n said direction and 1s actuated relav4l Y Y 1,715,180"

tively to said second-mentioned member by 10 mentioned member 4While the `seeond-menf` tioned operating member is held by the oper- 15 ator.

EDMUND WZEH. 

